An implant overdenture fits over a dental implant with various types of attachments that provide you with excellent stability and retention of your complete dentures. Most often, an upper overdenture will require placement of more implants than a lower overdenture due to the different nature of the anatomy of the upper and lower jaws. It may also be possible to fabricate an upper denture without a palate (roof of the mouth), which may be a more comfortable option for some patients.